1. Field of the Invention
The present invention generally relates to an image processing apparatus. More particularly, the present invention relates to an image processing apparatus capable of simultaneously reading both sides of a document.
2. Description of the Background Art
There are image processing apparatuses which have two reading portions for respectively reading both sides of a document (that is, front and back sides of a document) so that images on both sides of the document can be simultaneously read by one-time feeding without reversing the document. For example, a CCD (Charge Coupled Device) for reading an image on a front side of a document and a CIS (Contact Image Sensor) for reading an image on a back side of a document are provided on a transport path of a document feeder, and the CCD and the CIS read images on both sides of a document. Since there is no need to reverse a document, this structure reduces the time required to read images on both sides of a document, thereby implementing reduction in overall image processing speed.
A technology regarding an image processing apparatus capable of reading images on both sides of a document is disclosed in Japanese Patent Publication No. 2002-232671 of unexamined applications. According to this publication, image data read from both sides of the document is transmitted to the outside in an optimal order according to the transmission rate of the image data to the outside.
According to this publication, the data can be transmitted to the outside in an optimal order according to the transmission rate. Even though the order of transmitting the data is optimal according to the transmission rate to the outside, however, the order may not be optimal in the overall system of the image processing apparatus. Therefore, the image processing efficiency may not be appropriate.